Courtesy photo“Kidnapped at the Border” by Ramani Rangan, of Gloucester

Courtesy photo“Spirograph” by Gints Grinbergs, of Dedham

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Courtesy photo“Catenaria” by Joe Fix, of Newbury

There’s a lot to contemplate at this year’s Flying Horse Outdoor Sculpture Exhibit.

One work illustrates a concept from physics, while others address pressing social problems, such as “Sandy Hook, 2012” by Allen Spivack from Jamaica Plain.

“It’s in memory of the lives that were lost at Sandy Hook, and it’s made out of silver-plated cutlery,” said Judith Klein, who founded the exhibit. “His idea is that cutlery is something that is often valued in a family, passed down from generation to generation, and here we have it deformed and destroyed, to carry the weight of the destruction and eternal loss from that tragedy.”

Still other sculptures, including “Fordy Fred,” an egg-shaped figure made from aluminum street lamps by self-taught artist Steve Heller, celebrate the power of imagination that makes all art possible.

These are two of 50 sculptures by 41 artists that appear in this year’s show, which will be on the campus of Pingree School in Hamilton from Sunday, Sept. 1, through Saturday, Nov. 30.

“That’s pretty exciting, to imagine this has been happening this long,” said Klein, who lives in Beverly.

The public is invited to a reception with the artists Sunday, Sept. 15, at 1 p.m. at Pingree. Honorary Chair Yarrow Thorne, founder and artistic director of The Avenue Concept, a public art initiative in Providence, Rhode Island, will speak at the event.

Starting this weekend, visitors can pick up a catalog and map from a mailbox on campus or download an app with the same information to their smartphones, to help them locate and learn about sculptures on the school grounds.

“We’re actually placing a piece in the pond this year by Gints Grinbergs,” Klein said. “It’s a piece called ‘Spirograph,’ and it’s going to be placed on the rock in that pond.”

Two small, figurative busts by Salisbury artist Nancy Sander will be mounted at the entrance to the school’s new academic building, so “they won’t get lost.”

“One is called ‘Dude,’ this handsome man,” Klein said. “The other is ‘Spirit of Oak,’ a head with acorns on it.”

Newbury sculptor Joe Fix applies elements from his work as a structural engineer to his pieces, and he sees the two disciplines as complementary.

“To me, there’s a lot of creativity in engineering, and in sculpture, there’s always technical things that need to be worked out,” he said.

The piece he has installed at Pingree is formed by 12 red spheres, suspended in the air at different heights and forming an arc.

The work is named “Catenaria,” which is Spanish for catenary, a term from mathematics that describes a particular curved shape.

“If you took a linked chain and held it on two ends, the sag it would make would take the form of an inverted catenary,” Fix said.

When that curve is turned right side up, it forms an arch and supplies the shape used in doorways, ceilings and other structures designed by engineers.

Fix’s spheres — which are actually tether balls on wires — appear in the shape of an arch, where natural forces would normally push them together.

But instead, the spheres are separated from each other, as if the force of gravity was pulling them apart.

“In an arch shape, all the elements are ideally in compression, whereas in a structure like a suspension bridge, most of the elements in the cable are in tension,” Fix said. “I take an arch shape and make it out of elements that are in tension.”

He said he “really just wanted to express that shape,” but in a way, that is the opposite of how we expect to see it, which makes the underlying concept explicit for the viewer.

“I enjoy doing that, getting a smile out of someone and making them think about how they see things,” Fix said.

Where catenaries are a constant feature of the physical world, the situation evoked in a sculpture called “Kidnapped at the Border” is a current consequence of government policy.

“We’re still dealing with this incarceration of people,” said Ramani Rangan, the Gloucester artist who created the work. “I’m not concerned with whether it’s legal or not legal. I’m concerned from the level of what it means to be a parent and child, and what it means to be forcibly separated.”

Rangan, who has written a memoir called “Gathering Moments in Time,” was born in England to Indian parents, who became refugees during World War II.

In addition to living through the Blitz, when Nazis bombed civilians in London, Rangan’s family “went through racism that comes out when people are stressed.”

His sculpture at Pingree was made from supplies that he found at a local hardware store and focuses on the desperation of families that have been separated.

“I visualized these hands reaching into a cage, trying to get their loved ones out of the cage,” Rangan said.

As with a series of paintings that he made to protest drone strikes, Rangan is less interested in blaming particular parties, than in calling for change.

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